农田生态系统土壤CO2释放研究

采用静态箱和气相色谱法,对不同施肥条件(CK,NP,秸秆+NP)下的土壤呼吸进行了连续1年的观测研究。结果表明,土娄土农田土壤的呼吸速率呈明显的季节性变化,以7月上旬最大,冬季最小;土壤温度是影响土壤呼吸速率的主要因素,二者间存在极显著的幂函数相关关系(P<0.01);长时期夏季干旱造成的土壤水分胁迫也明显影响土壤呼吸速率;CK,NP和秸秆+NP3种培肥措施下,土壤CO2年排放量估计值分别为1353,1604和1769g/m2;不同培肥措施长期实施对土壤呼吸速率和CO2释放量有明显影响,其大小顺序为秸秆+NP>NP>CK。

Study on soil CO2emission in agri-ecosystems

Soil respiration was measured by static chamber and gas chromatogram method in agri-ecosystems with different long-term fertilization (CK,NP and Straw+NP).The results obtained in one year showed that the seasonal dynamics of soil respiration rate in Lou soil was obvious and relatively complex,and its maximum value appeared in the first ten days of July,while the lowest in winter.Soil respiration rate was significantly correlated with soil temperature,and could be described by power function (P<(0.01)).Soil water-stress led by longer drought in summer could also influence soil respiration rate obviously.From observed values and model predictions,the annual soil CO_2 emission in agri-ecosystems with different fertilizations was at 1 353 g/m~2 in farmland without fertilizer(CK),1 604 g/m~2 with NP chemical fertilizer (NP),and 1 769 g/m~2 with corn straw plus NP chemical fertilizer (Straw+NP).The soil respiration rate and annual soil CO_2 emission were affected significantly by different fertilization treatments,and its order was as follows:Straw+NP>NP>CK.